Shed-proof napped blanket fabric



June 5, 1962 F. T. SPENCER 3,037,262

SHED-PROOF NAPPED BLANKET FABRIC Filed Jan. 18, 1961 United StatesPatent Ofiice 3,fi37,262 Patented June 5, 1962 3,037,262 SHED-PROOFNAEPEE) BLANKET FABREC Francis T. Spencer, Biddeford, Maine, assigner toPepperell Manufacturing Company, Boston, Mass, a corporation ofMassachusetts Filed Jan. 13, 1961, Ser. No. 83,538 6 Claims. (Cl. 288t))This invention relates to napped or similar fabric, more especiallyblanket cloth having certain useful characteristics, some of which, inparticular, resistance to shedding, have been recognized heretofore asdesirable, but which have not been commercially attainable, at least asrespects fabric wherein the nap is predominantly of certain specificmaterials.

For the attainment of the above desired characteristics, it hasheretofore been proposed to treat the nap layer of the fabric as, forexample, by spraying it with a liquid of a kind such as chemically orphysically to change the character of the individual fibers; to causeadjacent fibers, where they contact, to coalesce; or to form a coatingupon the individual fibers which may or may not cause the fibers toadhere to each other, and then allowing or causing the treating mediumto dry, cure or set. However, such modes of treatment have in many caseshad the ultimate result of making the fabric dense and felt-like; ofdecreasing the loft of height of the nap; or of producing a nap having acrust-like surface having a distinctly different appearance and/ or feelfrom that which is demanded in the intended field of use of thematerial.

Some of the substances which have been employed in treating nappedmaterial are found among the synthetic resins while others are solutionsof certain inorganic salts. Thus, as flame-retardant materials forcotton, certain polymers made by reacting tris (l-aziriciinyl) phosphineoxide, referred to as APO, or tris (l-aziridinyl) phosphine sulfide,referred to as A'PS, with tetrakis (hydroxymethyl) phosphonium chloride,referred to as THPC have been employed. As water repellants for cotton,substances such as ODI (octadecyl isocyanate) have been empolyed, andfor crush-resistance the so-called Rohnite resins (which arewater-soluble urea formaldehyde resins), and the socalled Safe-Te-Setresins (which are cyclic urea resins), which are applied in watersolution, have been used.

While the method of preparing the fabric herein claimed may be founduseful in the treating of napped or similar fabrics for other purposes,the invention herein disclosed relates specifically to a novel blanketcloth characterized by its unusual resistance to the shedding of napduring customary use, or as the result of laundry treatment but which,at the same time, is soft and drapeable, lofty in feel and has thepleasing appearance of customary untreated napped blanket cloth. Whileherein the term napped fabric or napped blanket cloth is employed forconvenience, it is to be understood that this term is not to berestricted to a fabric having a layer of upstanding fibers such asproduced by passing a woven fabric through a conventional nappingmachine, but is to be considered as broadly inclusive of high-pilefabrics such as plushes and artificial furs made from textile materials.However, the invention is herein described by way of specific example asapplied to the manufacture of a non-shedding household blanket.

Since certain of the synthetic fibers have, in recent years, been widelyadopted in blanket manufacture, and because some of such fibers are veryslippery and more prone to shedding when constitutin a nap than thenatural fibers, interest in the reduction of shedding of blanket fibershas been intensified. Thus, for example, it has been proposed todecrease shedding of a blanket wherein Orion constitutes a substantialpercentage of the nap, first by treating the napped fabric by sprayingit with certain chemical substances and then subjecting it to heat,whereby the chemical so reacts with the material of the nap fibers as tosoften the surface of the fiber which has been wet by the chemical, withthe result that, when the fabric is allowed to cool, adjacent fiberscoalesce at their contact point thus providing an interlock whichsubstantially lessens the loss of nap during use. On the other hand,when a like treatment has been applied to blanket material where the napis predominantly cellulosic, for example rayon, although the insulatingvalue and wearing quality of the blanket are not adversely affected andloss of nap is somewhat reduced, the material, as heretofore so treated,shows a strong tendency to lose its original lofty appearance.Purchasers are greatly influenced by the appearance and feel of ablanket and thus would have a tendency to select an untreated blanketrather than that which has been treated. Moreover, since the cellulosicblanket, prepared as above, does shed nap to some extent, it would notbe premissible to mark such a blanket as shed-proof.

A principal object of the invention is to provide a truly shed-proofblanket whose nap is predominantly of cellulosic fiber, for examplerayon; which sulfers no apparent loss of loft by reason of the treatmentto which it is subjected in making it shed-proof, and whose feel andappearance, as compared with a freshly napped blanket, are notsubstantially modified, or may even be improved. A further object is toprovide a blanket fabric which is substantially shed-proof and whereinthe nap fibers are individually coated and adhesively bonded togetherand are substantially perpendicular to the plane of the main body of thefabric. A further object is to provide a substantially shed-proof nappedfabric wherein adjacent n-ap fibers are bonded together by a materialother than the substance of the fiber itself, and wherein individual napfibers occupy approximately the same relative positions as they did inthe fabric at the completion of the napping operation. A further objectis to provide a shed-proof blanket which is free from any chemicalsubstance which might be harmful to a small child who might chew or suckthe fabric. A further object is to provide a napped blanket fabricwherein the nap is predominantly cellulosic and which is shed-proof.

A further object is to provide shed-proof blanket cloth which is softand drapeable and which comprises a body portion of conventional weaveand which has a layer of nap fibers projecting from one side at least ofthe body portion, the nap fibers being predominantly cellulosic and thebody portion possessing substantially the same characteristics as whenfreshly woven, while the nap is substantially the same, with respect toappearance, color, feel and loft, with the nap fibers predominantlyupstanding, as when newly napped, and wherein the nap fibers have thesame chemical characteristics which they had in the fabric as woven, andcomprising means where individual nap fibers are so permanently bondedtogethe as substantially to reduce the shedding of the nap when thefabric is exposed to conditions simulating those of blanket fabric underordinary conditions of use. A further object is to provide shed-proofblanket cloth which is soft and drapeable and which comprises a bodyportion of woven cellulosic material and a layer of nap fibersprojecting from one side, at least, of said body fabric-the nap fibersbeing predominantly of rayon and the body portion retainingsubstantially the same characteristics as when newly woven, while thenap fibers are substantially the same with respect to appearance, feeland loft as when freshly napped, and wherein individual nap fibers arecoated with an acryl- O ic polymer which so bonds them together assubstantially to prevent shedding of the nap during the use of theblanket cloth.

answer;

Other and further objects and advantages of the invention will bepointed out in the following more detailed description and by referenceto the accompanying drawings wherein:

FIG. 1 is a diagrammatic elevation or flow-sheet, illustrative of thesuccessive steps in the process; and

FIG. 2 is a fragmentary vertical section, to larger scale than FIG. 1,illustrative of the step of raising the nap fibers while they are stillWet with a treating liquid.

During the research which resulted in the present invention, it wasdiscovered that when napped fabric, wherein the nap was predominantly ofacrylic material such, for example, as Acrylan, was first sprayed with acertain acrylic emulsion in water dispersion so as to coat the napfibers, and then the fabric was baked at a temperature of approximately300 F., a coating was formed upon the nap which permanently bondedadjacent fibers toeach other to an extent such as substantially toreduce the shedding of the nap when the fabric was exposed to conditionssimulating those of blanket fabric under ordinary conditions of use. Thechemical employed did not alter the chemical structure or physicalproperties of the individual fibers and since, after heat-treatment, itwas completely insoluble in Water, the finish thus provided became apermanent part of the blanket and continued to oppose sheddingthroughout the useful life of the fabric. It may be noted that acrylicfibers have a natural resiliency, not possessed by cellulosic fibers andare hydrophobic in nature, and because of these two qualities, treatedacrylic blankets are not altered perceptibly in appearance as comparedwith the untreated fabric and retain their original loft and resilienceso that sales appeal is not lessened by reason of this particulartreatment.

Experiments with blanket cloth made predominantly of cellulosic fibersand subjected to the above treatment, are also, to a certain extent,shed-resistant. However, it was observed that blankets, so treated,showed a tendency to lose the initial lofty appearance and feel of theuntreated fabric as it exists when the initial napping has just beencompleted. Such a blanket, while useful for its intended purpose, didnot have an appearance such as to recommend it to the puchaser. In theeffort to make a cellulosic nap fully shed-resistant, it was proposed tomodify the above treatment by increasing the concentration of thechemical. This was carried out to the point at which a crust of chemicalwas formed on the opposite faces of the blanket. While the resultantfabric was actually shed-proof, it had lost loft-that is to say, thethickness of the nap layer was less than in the untreated fabric, whilethe presence of the crust imparted an appearance and feel suggestive ofmaterials heretofore proposed for blankets, but which are in the muchlower price range as compared with blankets of nappcd woven textilefabric. Attempts to dispose of this crust so as to restore the feel andappearance of the original nappcd fabric, as by breaking up or otherwisemodifying or removing this crust, after once having been formed, werewholly unsuccessful. Even though the treated material were again passedthrough the napping machine, the resultant fabric did not have the sameappearance as when first nappcd and, moreover, the action of the nappingmachine was such as to break the bond which had been provided betweenthe nap fibers, so that the net result was to produce a material whichwas inferior to the original untreated nappcd fabric. The desiredresults were eventually attained by first spraying the nappcd materialwith the selected chemical, as above described, but at a concentrationlowe than such as would form a crust; then, while the material was stillwet with the spraying material, raising the map to its original heightor even higher, and then, without applying pressure (as by passing thematerial between rollers), subjecting it to a heat-treatment whereby thenap fibers, in their raised position, were bonded together by thecoating chemical so that the blanket became shed-proof and had a feeland appearance, but little different and, if anything with a higher loftand softer feel than a nappcd blanket which has just passed through thenapping machine.

Referring to the drawings, the character N indicates, in a diagrammaticmanner, a napping machine of ordinary type, wherein the woven cloth Cpasses betwccn rolls It and 11, clothed with the usual pin-coverednapping fabric which, by engagement with the yarns forming the initialwoven cloth, raises some of the constituent fibers of the yarns to forma nap on the opposite surfaces of the body of the cloth. This cloth Cwith nap at its opposite surfaces, is then desirably temporarily storedin any convenient way in readiness for the novel treatment according tothe present invention. For example, the cloth may be laid in folds upona truck, or in a box or other portable container and, in this condition,moved to the vicinity of the treating apparatus. As diagrammaticallyillustrated in FIG. 1, the treating apparatus desirably comprises aconventional tenter frame T having the customary parallel, constantlytravelling chains (not shown), provided with pins or clamps which engagethe opposite selvage edges of the fabric and hold the fabric undertransverse tension while moving it along progressively, in the directionof the arrow A, with its nappcd surface in a horizontal plane, and outof contact with solid rollers, or any other elements such as would tendto crush or compress the nap. As the fabric is so moved, spray heads S,of any suitable type, and which are supplied with the coating materialunder pressure, deliver this matcrial as a liquid spray against theopposite faces of the fabric. One material which has been foundeminently suitable for the purpose is an aqueous dispersion of anacrylic polymer known to the trade as Rhoplex HA8, which is made by thefirm of Rohm & Haas of Washington Square, Philadelphia 5, Pennsylvania.Materials of this class are described in the Supplement to the 1953edition of Handbook of Materials and Trade Names, (published byindustrial Research Service, Dover, New Hampshire), under the genericname Rhoplex Emulsion, an aqueous dispersion of acrylic polymers which,when deposited from dispersion in water, forms a transparent film.

In accordance with the present invention, the dispersion of thischemical in water is within the range of 93% to 93 /2% water and from 1/2% of chemical to 7% chemical. However, it is contemplated that thisrange may be extended slightly in either direction. As applied in thisdilution, the chemical is not appreciably sticky, so that it flowsfreely and is readily absorbed by the nap layer. The liquid dispersionis applied to the cloth within the range of from 10% to 15% by weight ofliquid to cloth and, here again, the range may be varied slightly up ordown.

The fabric, afte having een sprayed in this manner, is advanced (FIG. 1)between two sets 12 and 13, respectively, of freely rotatable rollersone set of rollers being above the cloth and the other below it and withtheir axes so arranged that the cloth must follow a sinuous path inpassing between the upper and lower rolls. Rolls of 4 inches, extremeoutside diameter, have been found useful for the purpose, although it iscontemplated that rolls of other sizes may be employed, it beingadvantageous to use rolls of such size and so arranged as to provide asubstantial period of contact of the cloth with the rolls. These rolls,as illustrated diagrammatically in FIG. 2, have cylindrical corescovered, for example, with mapper-roll cloth, using pins P of the elbowtype having a 45 bend, but it is contemplated that other types of pinmay be found useful. Upper and lower rolls, as shown at 12a and 13a inFIG. 2, are so arranged that the points of their pins are directedtoward the oncoming fabric-it being noted that the fabric iscontinuously advanced by the chains of the tenter frame in the directionof the arrow A (FIG. 1). The rolls are free to turn and are turned onlyby the frictional drag of the cloth.

As the cloth progresses, the tips of the pins enter the nap layer and soagitate the nap as to induce the liquid to enter more deeply into thenap layer. Then, as the rolls turn, and the angle of the pins changes,in relation to the plane of the cloth, they tend to raise the nap, thatis, to move te pile fibers into perpendicularity relatively to the bodyof the fabric, resulting in a smooth even surface and a loftier nap thanresults from the conventional napping operation.

After leaving the sets 12 and 13 of rolls, the fabric is advancedthrough a housing H having therein any suitable type of heating meanshere illustrated as infrared lamps L-the treating chamber being longenough so that the liquid carrier for the chemical is graduallyevaporated. A minimum temperature in the heating chamber ofapproximately 250 F. is useful for the purpose, although it is preferredto increase the temperature to approximately 300 F. to speed up theoperation. As the material C travels through the heating zone, and thewater evaporates, the chemical concentrates and first forms a stickycoating on the nap fibers so that adjacent fibers, where they contact,adhere to each other, and then sets to form a permanent bond.

While the above mode of treatment is particularly useful for thetreatment of rayon or other cellulose fibers, the raising of the napwhile wet with the chemical, appears to improve the character of acrylicblankets, or other napped materials, beyond that which is the result ofprevious methods of treatment for the prevention of nap shed-ding(whether by the use of the above acrylic polymer emulsion, or otherchemicals).

The result of this treatment not only makes the material trulyshed-proof, but appears to impart to the mapped fabric a quality whichhas not heretofore been obtained by any previous method and it iscontemplated that any napped fabric thus treated will have a loft andappearance superior to that of fabric which has been freshly napped butnot otherwise treated.

While one desirable method of producing the novel fabric of the presentinvention and instrumentalities whereby it may be practiced has hereinbeen described by way of example, it is to be understood that theinvention is broadly inclusive of any fabric within the scope of theappended claims regardless of the apparatus employed in its production.

I claim:

1. A shed-proof blanket cloth which is soft and drapeable and whichcomprises a body portion of woven fabric having a layer of nap fibersprojecting from one side, at least, of the body fabric, the nap fibersbeing predominantly cellulosic, said blanket cloth being substantiallythe same with respect to appearance, feel, color and loft, and with thenap fibers predominantly upstanding, as when freshly napped, thenap-forming fibers having the same chemical characteristics which theyhad in the fabric as woven, individual nap fibers comprised in saidlayer being coated witha material which provides -a permanent bondwhereby adjacent nap fibers are permanently united so as substantiallyto prevent the shedding of the nap during the use of the blanket clothwhile the body fabric is substantially free from said coating material.

2. Blanket cloth according to claim 1, wherein the body fabric ispredominantly cellulosic and the coating material, which coats the napfibers, is an acrylic polymer.

3. Blanket cloth according to claim 1, wherein the nap fibers arepredominantly rayon and the coating material is Rhoplex HA-8.

4. Blanket cloth according to claim 1, wherein the coating upon theindividual nap fibers is such as results from the evaporation of anacrylic polymer from a water dispersion in the approximate proportion of93% water and 7% resin.

5. Blanket cloth according to claim 1, wherein the fabric body has alayer of nap at each side, respectively, and wherein fibers, comprisedin each respective layer, are permanently bonded together by an adhesivecoating.

6. A soft, d-rapeable, shed-proof blanket cloth com prising a woven bodyfabric having a layer of nap fibers projecting from one side, at least,of the body fabric, the nap fibers being predominantly of rayon, thebody fabric retaining substantially the same characteristics as whennewly woven, and the nap layer being substantially the same, withrespect to appearance, feel and loft of nap and the nap fibers beingpredominantly upstanding, as when freshly napped, the nap-forming fibershaving the same chemical and physical characteristics which they had inthe fabric as woven, the individual nap fibers being coated with anacrylic polymer which so permanently bonds them together assubstantially to reduce the shedding of the nap when the fabric isexposed to the usual conditions of use while the body portion of thefabric is substantially free from said coating material.

References Cited in the file of this patent UNITED STATES PATENTS2,329,651 Powers et al. Sept. 14, 1943 2,590,713 Libbey Mar. 25, 19522,639,240 Ehle May 19, 1953 2,641,045 Meister et al. June 9, 19532,656,586 Cowie et al. Oct. 27. 1953

1. A SHED-PROOF BLANKET CLOTH WHICH IS SOFT AND DRAPEABLE AND WHICHCOMPRISES A BODY PORTION OF WOVEN FABRIC HAVING A LAYER OF NAP FIBERSPROJECTING FROM ONE SIDE, AT LEAST, OF THE BODY FABRIC, THE NAP FIBERSBEING PREDOMINANTLY CELLULOSIC, SAID BLANKET CLOTH BEING SUBSTANTIALLYTHE SAME WITH RESPECT TO APPEARANCE, FEEL, COLOR AND LOFT, AND WITH THENAP FIBERS PREDOMINANTLY UPSTANDING, AS WHEN FRESHLY NAPPED, THENAP-FORMING FIBERS HAVING THE SAME CHEMICAL CHARACTERISTICS WHICH THEYHAD IN THE FABRIC AS WOVEN, INDIVIDUAL NAP FIBERS COMPRISED IN SAIDLAYER BEING COATED WITH A MATERIAL WHICH PROVIDES A PERMANENT BONDWHEREBY ADJACENT NAP FIBERS ARE PERMANENTLY UNITED SO AS SUBSTANTIALLYTO PREVENT THE SHEDDING OF THE NAP DURING THE USE OF THE BLANKET CLOTHWHILE THE BODY FABRIC IS SUBSTANTIALLY FREE FROM SAID COATING MATERIAL.